The relationship between peritumoral brain edema and the expression of vascular endothelial growth factor and its receptors in intracranial meningiomas

We examined the radiological and histological features of, and the influences of the expression of VEGF and its two major receptors, Flt-1 and Flk-1, on the development of peritumoral brain edema (PTBE) in patients with intracranial meningiomas. The expressions of VEGF and VEGF receptors in the immunohistochemical study were analyzed in relation to several factors, including tumor size, location, vascularity, and blood supply, as seen on digital subtraction angiographic studies. The edema volume (P = 0.0003) and edema index (P < 0.0001) had a significantly positive relation to VEGF expression. The positivity of Flt-1 and Flk-1 was mainly observed in tumor vessels; 44 cases (37.2%) were positive for the Flt-1 antibody and 37 cases (31.4%) for the Flk-1 antibody. The mean value of the edema index of the positive-Flt-1 group (5.220 ± 11.586) was significantly higher than that of the negative-Flt-1 group (1.782 ± 2.559) (P < 0.0001). The mean value of the edema index of the positive-Flk-1 group (3.925 ± 5.870) was slightly higher than that of the negative-Flk-1 group (2.671 ± 8.136) (P < 0.0001). Our data suggest that the expressions of VEGF and VEGF receptors positively relate to each other and to the formation of PTBE in patients with meningiomas.